This invention relates to vehicle seats. It is conventional in two-door motor cars to mount the driver's and front passenger seats on pivots located below the forward portions of the seats, so that the seats can be tipped forwardly to increase clearance space behind these seats and enable access to be had to any luggage space or rear seat of the car. The extent of tipping movement possible is usually limited by the backrest coming into contact with the steering wheel, instrument panel or possibly the windscreen, and a problem arises because the lower part of the seat and back moves in an arc about a smaller radius than the top of the seat back, and hence moves through a smaller distance fore and aft, and this restricts access at positions near the floor of the vehicle.
To overcome the aforementioned problem it has been suggested to mount the seat cushion frame for sliding movement in a fore and aft direction, and to use the backrest as a lever by pivoting it at its lower end to a fixed point relative to the vehicle and pivoting near its lower end to the seat cushion frame. This enables the whole seat cushion to be translated forwardly and increase the clearance behind the seat particularly at the lower level, when the backrest is tipped. However, rattle or vibration, particularly of an unoccupied seat, is always a problem with vehicle seat design where any capability for movement is provided, and in practice it is found that if guides or slides mounting the seat cushion frame for its fore and aft movement are sufficiently loose to allow free sliding during the tipping of the backrest, vibration and rattle when the seat is unoccupied is a serious problem, and if the slides or guides are made tighter, the sliding movement is only accomplished with difficulty. Additionally constructions of this kind have hitherto had the seat cushion spaced well above the floor of the vehicle in order to provide clearance for associated adjusting devices, which has led to the cushion being supported on a pedestal frame and it has been found that this increases the possibility of distortion occurring, and hence of jamming for example if grit becomes trapped in the slides.